Download Creating False Memories Elizabeth F. Loftus

Creating False Memories Elizabeth F. Loftus
In 1986 Nadean Cool, a nurse's aide in Wisconsin, sought therapy from a psychiatrist to help her cope
with her reaction to a traumatic event experienced by her daughter. During therapy, the psychiatrist used
hypnosis and other suggestive techniques to dig out buried memories of abuse that Cool herself had
allegedly experienced. In the process, Cool became convinced that she had repressed memories of having
been in a satanic cult, of eating babies, of being raped, of having sex with animals and of being forced to
watch the murder of her eight-year-old friend. She came to believe that she had more than 120
personalities-children, adults, angels and even a duck-all because, Cool was told, she had experienced
severe childhood sexual and physical abuse. The psychiatrist also performed exorcisms on her, one of
which lasted for five hours and included the sprinkling of holy water and screams for Satan to leave
Cool's body.
When Cool finally realized that false memories had been planted, she sued the psychiatrist for
malpractice. In March 1997, after five weeks of trial, her case was settled out of court for $2.4 million.
Nadean Cool is not the only patient to develop false memories as a result of questionable therapy. In
Missouri in 1992 a church counselor helped Beth Rutherford to remember during therapy that her father,
a clergyman, had regularly raped her between the ages of seven and 14 and that her mother sometimes
helped him by holding her down. Under her therapist's guidance, Rutherford developed memories of her
father twice impregnating her and forcing her to abort the fetus herself with a coat hanger.The father had
to resign from his post as a clergyman when the allegations were made public. Later medical examination
of the daughter revealed, however, that she was still a virgin at age 22 and had never been pregnant. The
daughter sued the therapist and received a $1-million settlement in 1996.
About a year earlier two juries returned verdicts against a Minnesota psychiatrist accused of planting false
memories by former patients Vynnette Hamanne and Elizabeth Carlson, who under hypnosis and sodium
amytal, and after being fed misinformation about the workings of memory, had come to remember
horrific abuse by family members. The juries awarded Hammane $2.67 million and Carlson $2.5 million
for their ordeals.
In all four cases, the women developed memories about childhood abuse in therapy and then later denied
their authenticity. How can we determine if memories of childhood abuse are true or false? Without
corroboration, it is very difficult to differentiate between false memories and true ones. Also, in these
cases, some memories were contrary to physical evidence, such as explicit and detailed recollections of
rape and abortion when medical examination confirmed virginity. How is it possible for people to acquire
elaborate and confident false memories? A growing number of investigations demonstrate that under the
right circumstances false memories can be instilled rather easily in some people.
My own research into memory distortion goes back to the early 1970s, when I began studies of the
"misinformation effect." These studies show that when people who witness an event are later exposed to
new and misleading information about it, their recollections often become distorted. In one example,
participants viewed a simulated automobile accident at an intersection with a stop sign. After the viewing,
half the participants received a suggestion that the traffic sign was a yield sign. When asked later what
traffic sign they remembered seeing at the intersection, those who had been given the suggestion tended
to claim that they had seen a yield sign. Those who had not received the phony information were much
more accurate in their recollection of the traffic sign.
My students and I have now conducted more than 200 experiments involving over 20,000 individuals that
document how exposure to misinformation induces memory distortion. In these studies, people "recalled"
a conspicuous barn in a bucolic scene that contained no buildings at all, broken glass and tape recorders
that were not in the scenes they viewed, a white instead of a blue vehicle in a crime scene, and Minnie
Mouse when they actually saw Mickey Mouse. Taken together, these studies show that misinformation
can change an individual's recollection in predictable and sometimes very powerful ways.
Misinformation has the potential for invading our memories when we talk to other people, when we are
suggestively interrogated or when we read or view media coverage about some event that we may have
experienced ourselves. After more than two decades of exploring the power of misinformation,
researchers have learned a great deal about the conditions that make people susceptible to memory
modification. Memories are more easily modified, for instance, when the passage of time allows the
original memory to fade.
False Childhood Memories
It is one thing to change a detail or two in an otherwise intact memory but quite another to plant a false
memory of an event that never happened. To study false memory, my students and I first had to find a
way to plant a pseudomemory that would not cause our subjects undue emotional stress, either in the
process of creating the false memory or when we revealed that they had been intentionally deceived. Yet
we wanted to try to plant a memory that would be at least mildly traumatic, had the experience actually
happened.
My research associate, Jacqueline E. Pickrell, and I settled on trying to plant a specific memory of being
lost in a shopping mall or large department store at about the age of five. Here's how we did it. We asked
our subjects, 24 individuals ranging in age from 18 to 53, to try to remember childhood events that had
been recounted to us by a parent, an older sibling or another close relative. We prepared a booklet for
each participant containing one-paragraph stories about three events that had actually happened to him or
her and one that had not. We constructed the false event using information about a plausible shopping trip
provided by a relative, who also verified that the participant had not in fact been lost at about the age of
five. The lost-in-the-mall scenario included the following elements: lost for an extended period, crying,
aid and comfort by an elderly woman and, finally, reunion with the family.
After reading each story in the booklet, the participants wrote what they remembered about the event. If
they did not remember it, they were instructed to write, "I do not remember this." In two follow-up
interviews, we told the participants that we were interested in
examining how much detail they could remember and how their
memories compared with those of their relative. The event
paragraphs were not read to them verbatim, but rather parts
were provided as retrieval cues. The participants recalled
something about 49 of the 72 true events (68 percent)
immediately after the initial reading of the booklet and also in
each of the two follow-up interviews. After reading the booklet,
seven of the 24 participants (29 percent) remembered either
partially or fully the false event constructed for them, and in the
two follow-up interviews six participants (25 percent) continued
to claim that they remembered the fictitious event. Statistically,
there were some differences between the true memories and the false ones: participants used more words
to describe the true memories, and they rated the true memories as being somewhat more clear. But if an
onlooker were to observe many of our participants describe an event, it would be difficult indeed to tell
whether the account was of a true or a false memory. Of course, being lost, however frightening, is not
the same as being abused. But the lost-in-the-mall study is not about real experiences of being lost; it is
about planting false memories of being lost. The paradigm shows a way of instilling false memories and
takes a step toward allowing us to understand how this might happen in real-world settings. Moreover, the
study provides evidence that people can be led to remember their past in different ways, and they can
even be coaxed into "remembering" entire events that never happened.
Studies in other laboratories using a similar experimental procedure have produced similar results. For
instance, Ira Hyman, Troy H. Husband and F. James Billing of Western Washington University asked
college students to recall childhood experiences that had been recounted by their parents. The researchers
told the students that the study was about how people remember shared experiences differently. In
addition to actual events reported by parents, each participant was given one false event either an
overnight hospitalization for a high fever and a possible ear infection, or a birthday party with pizza and a
clown that supposedly happened at about the age of five. The parents confirmed that neither of these
events actually took place.
Hyman found that students fully or partially recalled 84 percent of the true events in the first interview
and 88 percent in the second interview. None of the participants recalled the false event during the first
interview, but 20 percent said they remembered something about the false event in the second interview.
One participant who had been exposed to the emergency hospitalization story later remembered a male
doctor, a female nurse and a friend from church who came to visit at the hospital. In another study, along
with true events Hyman presented different false events, such as accidentally spilling a bowl of punch on
the parents of the bride at a wedding reception or having to evacuate a grocery store when the overhead
sprinkler systems erroneously activated. Again, none of the participants recalled the false event during the
first interview, but 18 percent remembered something about it in the second interview. For example,
during the first interview, one participant, when asked about the fictitious wedding event, stated, "I have
no clue. I have never heard that one before." In the second interview, the participant said, "It was an
outdoor wedding, and I think we were running around and knocked something over like the punch bowl
or something and made a big mess and of course got yelled at for it. "
Imagination Inflation
The finding that an external suggestion can lead to the construction of false childhood memories helps us
understand the process by which false memories arise. It is natural to wonder whether this research is
applicable in real situations such as being interrogated by law officers or in psychotherapy. Although
strong suggestion may not routinely occur in police questioning or therapy, suggestion in the form of an
imagination exercise sometimes does. For instance, when trying to obtain a confession, law officers may
ask a suspect to imagine having participated in a criminal act. Some mental health professionals
encourage patients to imagine childhood events as a way of recovering supposedly hidden memories.
Surveys of clinical psychologists reveal that 11 percent instruct their clients to "let the imagination run
wild," and 22 percent tell their clients to "give free rein to the imagination." Therapist Wendy Maltz,
author of a popular book on childhood sexual abuse, advocates telling the patient: "Spend time imaging
that you were sexually abused, without worrying about accuracy
proving anything, or having your ideas make sense .... Ask yourself ...
these questions: What time of day is it? Where are you? Indoors or
outdoors? What kind of things are happening? Is there one or more
person with you?" Maltz further recommends that therapists continue
to ask questions such as "Who would have been likely perpetrators?
When were you most vulnerable to sexual abuse in your life?"
The increasing use of such imagination exercises led me and several
colleagues to wonder about their consequences. What happens when
people imagine childhood experiences that did not happen to them?
Does imagining a childhood event increase confidence that it
occurred? To explore this, we designed a three-stage procedure. We
first asked individuals to indicate the likelihood that certain events
happened to them during their childhood. The list contains 40 events,
each rated on a scale ranging from "definitely did not happen" to
"definitely did happen." Two weeks later we asked the participants to imagine that they had experienced
some of these events. Different subjects were asked to imagine different events. Sometime later the
participants again were asked to respond to the original list of 40 childhood events, indicating how likely
it was that these events actually happened to them. Consider one of the imagination exercises. Participants
are told to imagine playing inside at home after school, hearing a strange noise outside, running toward
the window, tripping, falling, reaching out and breaking the window with their hand. In addition, we
asked participants questions such as "What did you trip on? How did you feel?" In one study 24 percent
of the participants who imagined the broken-window scenario later reported an increase in confidence that
the event had occurred, whereas only 12 percent of those who were not asked to imagine the incident
reported an increase in the likelihood that it had taken place. We found this "imagination inflation" effect
in each of the eight events that participants were asked to imagine. A number of possible explanations
come to mind. An obvious one is that an act of imagination simply makes the event seem more familiar
and that familiarity is mistakenly related to childhood memories rather than to the act of imagination.
Such source confusion when a person does not remember the source of information can be especially
acute for the distant experiences of childhood.
Studies by Lyn Giff and Henry L. Roediger III of Washington University of recent rather than childhood
experiences more directly connect imagined actions to the construction of false memory. During the
initial session, the researchers instructed participants to perform the stated action, imagine doing it or just
listen to the statement and do nothing else. The actions were simple ones: knock on the table, lift the
stapler, break the toothpick, cross your fingers, roll your eyes. During the second session, the participants
were asked to imagine some of the actions that they had not previously performed. During the final
session, they answered questions about what actions they actually performed during the initial session.
The investigators found that the more times participants imagined an unperformed action, the more likely
they were to remember having performed it.
Impossible Memories
It is highly unlikely that an adult can recall genuine episodic memories from the first year of life, in part
because the hippocampus, which plays a key role in the creation of memories, has not matured enough to
form and store longlasting memories that can be retrieved in adulthood.
A procedure for planting "impossible" memories about experiences that occur shortly after birth has been
developed by the late Nicholas Spanos and his collaborators at Carleton University. Individuals are led to
believe that they have well-coordinated eye movements and visual exploration skills probably because
they were born in hospitals that hung swinging, colored mobiles over infant cribs. To confirm whether
they had such an experience, half the participants are hypnotized, age-regressed to the day after birth and
asked what they remembered. The other half of the group participates in a "guided mnemonic
restructuring" procedure that uses age regression as well as active encouragement to re-create the infant
experiences by imagining them.. Spanos and his co-workers found that the vast majority of their subjects
were susceptible to these memory-planting procedures. Both the hypnotic and guided participants
reported infant memories. Surprisingly, the guided group did so somewhat more (95 versus 70 percent).
Both groups remembered the colored mobile at a relatively high rate (56 percent of the guided group and
46 percent of the hypnotic subjects). Many participants who did not remember the mobile did recall other
things, such as doctors, nurses, bright lights, cribs and masks. Also, in both groups, of those who reported
memories of infancy, 49 percent felt that they were real memories, as opposed to 16 percent who claimed
that they were merely fantasies. These findings confirm earlier studies that many individuals can be led to
construct complex, vivid and detailed false memories via a rather simple procedure. Hypnosis clearly is
not necessary.
How False Memories Form
In the lost-in-the-mall study, implantation of false memory occurred when another person, usually a
family member, claimed that the incident happened. Corroboration of an event by another person can be a
powerful technique for instilling a false memory. In fact, merely claiming to have seen a person do
something can lead that person to make a false confession of wrongdoing.
This effect was demonstrated in a study by Saul M. Kassin and his colleagues at Williams College, who
investigated the reactions of individuals falsely accused of damaging a computer by pressing the wrong
key. The innocent participants initially denied the charge, but when a confederate said that she had seen
them perform the action, many participants signed a confession, internalized guilt for the act and went on
to confabulate details that were consistent with that belief. These findings show that false incriminating
evidence can induce people to accept guilt for a crime they did not commit and even to develop memories
to support their guilty feelings.
Research is beginning to give us an understanding of how false memories of complete, emotional and
self-participatory experiences are created in adults. First, there are social demands on individuals to
remember; for instance, researchers exert some pressure on participants in a study to come up with
memories. Second, memory construction by imagining events can be explicitly encouraged when people
are having trouble remembering. And, finally, individuals can be encouraged not to think about whether
their constructions are real or not. Creation of false memories is most likely to occur when these external
factors are present, whether in an experimental setting, in a therapeutic setting or during everyday
activities.
False memories are constructed by combining actual memories with the content of suggestions received
from others. During the process, individuals may forget the source of the information. This is a classic
example of source confusion, in which the content and the source become dissociated.
Of course, because we can implant false childhood memories in some individuals in no way implies that
all memories that arise after suggestion are necessarily false. Put another way, although experimental
work on the creation of false memories may raise doubt about the validity of long-buried memories, such
as repeated trauma, it in no way disproves them. Without corroboration, there is little that can be done to
help even the most experienced evaluator to differentiate true memories from ones that were suggestively
planted.
The precise mechanisms by which such false memories are constructed await further research. We still
have much to learn about the degree of confidence and the characteristics of false memories created in
these ways, and we need to discover what types of individuals are particularly susceptible to these forms
of suggestion and who is resistant.
As we continue this work, it is important to heed the cautionary tale in the data we have already obtained:
mental health professionals and others must be aware of how greatly they can influence the recollection of
events and of the urgent need for maintaining restraint in situations in which imagination is used as an aid
in recovering presumably lost memories.
The Author: ELIZABETH F. LOFTUS is professor of psychology and adjunct professor of law at the University of
Washington. She received her Ph.D. in psychology from Stanford University in 1970. Her research has focused on human
memory, eyewitness testimony and courtroom procedure. Loftus has published 18 books and more than 250 scientific articles and
has served as an expert witness or consultant in hundreds of trials, including the McMartin preschool molestation case. Her book
Eyewitness Testimony won a National Media Award from the American Psychological Foundation. She has received honorary
doctorates from Miami University, Leiden University and John Jay College of Criminal Justice. Loftus was recently elected
president of the American Psychological Society.
Scientific American
September 1997, vol 277 #3
pages 70-75